At present, studies are undertaken regarding LTE (Long Term Evolution), which is the next-generation mobile communication system. The physical channel in LTE is described in Non-Patent Document 1. In the physical layer in LTE, the downlink from the base station device (hereinafter referred to as eNB “evolved Node B” as well) to the mobile station device (hereinafter referred to as UE “user equipment” as well) is constituted by downlink physical channels and downlink physical signals.
In this case, the downlink physical signals are constituted by a reference signal and a synchronization signal. The reference signal includes a cell-specific reference signal, a UE-specific reference signal, and an MBSFN reference signal. The synchronization signal and the cell-specific reference signal are signals required for the UE to detect a cell, and signals required for channel demodulation.
A study is undertaken regarding the use of the use of a relay node (RN, hereinafter referred to as “relay station device”) that relays signals at the UE and eNB. The RN is connected to the network via a specific eNB, the eNB that connects the RN being known as a donor eNB.
As donor nodes, a Type 1, which has a physical ID different from the donor eNB, and a Type 2, which does not have a cell different from the eNB are defined.
An UE that uses a Type 1 RN for relaying calculates and feeds back the CQI (channel quality index) from the SINR (signal-to-interference-plus-noise ratio) of the cell-specific reference signal received from the RN, and from the receiving performance. The RN selects an appropriate resource in response to the received CQI, determines an MCS (modulation and coding scheme) and transmits these to the UE.